package com.jay.base.thread.book;

import java.util.Random;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

/**
 * Created by caoyuan7 on 2019/7/24.
 *
 * 读写锁
 */
public class ReadWriteLockDemo {
    private static Lock lock = new ReentrantLock();
    private static ReentrantReadWriteLock readWriteLock = new ReentrantReadWriteLock();
    private static  Lock readLock = readWriteLock.readLock();
    private static  Lock writeLock = readWriteLock.writeLock();
    private int value;

    public Object handleRead(Lock lock) throws InterruptedException {
        try {
            lock.lock();
            Thread.sleep(1000);
            return value;
        }finally {
            lock.unlock();
        }
    }

    public void handleWrite(Lock lock,int index) throws InterruptedException {
        try {
            lock.lock();
            Thread.sleep(1000);
            value=index;
        }finally {
            lock.unlock();
        }
    }

    public static void main(String args[]){
        final ReadWriteLockDemo demo = new ReadWriteLockDemo();
        Runnable readRunnale = new Runnable() {
            @Override
            public void run() {
                try {
//                    demo.handleRead(readLock);
                    demo.handleRead(lock);
                }catch (InterruptedException e){
                    e.printStackTrace();
                }
            }
        };
        Runnable writeRunnale = new Runnable() {
            @Override
            public void run() {
                try {
//                    demo.handleWrite(writeLock,new Random().nextInt());
                    demo.handleWrite(lock,new Random().nextInt());
                }catch (InterruptedException e){
                    e.printStackTrace();
                }
            }
        };
        for(int i =0;i<18;i++){
            new Thread(readRunnale).start();
        }
        for(int i =18;i<20;i++){
            new Thread(writeRunnale).start();
        }

    }
}
